Broad-winged Hawk Research 2023

Jim Armbruster – Field Research Coordinator

Broad-winged Hawk nestlings in a stick nest. Credit M. Walsh

Several months following Broad-winged Hawks around Vermont culminated in a successful trapping expedition with researchers from Hawk Mountain Sanctuary’s Broad-winged Hawk Project. In early July Laurie Goodrich and Rebecca McCabe joined us with the goal of deploying GPS transmitters on local birds. VINS staff and volunteers began monitoring these elusive forest hawks as soon as they returned to the state from migration in preparation for Hawk Mountain’s arrival. We spent many hours finding active territories in hopes of locating nest sites with several identified around the VINS Nature Center in Quechee.

The Hawk Mountain team joined us at these territories where we attempted to trap an adult parent from near the nest. They planned to spend three days trapping with us but the rain had other plans. In their “downtime” they continued searching for nests and were able to find two more in one day. When the rain finally broke we travelled to the first nest site to set up a trap.

Trapping consisted of setting up mist nets around a robotic Great Horned Owl decoy. A blind was setup nearby where we played great horned calls to attract the attention of the parents. Within a few minutes of starting calls an angry broad wing adult answered. The bird quickly dive bombed the decoy and became tangled in the mist nets. As we removed the first bird, a second adult began calling from the trees. We moved the first bird out of sight and reset the trap and within minutes had both adults in hand.

Male and female comparison from first nest site. Female on left, male on right. Credit L. Goodrich

We collected morphometric data and attached a GPS transmitter backpack to the female, as she was large enough to carry the weight of the unit, and quickly released both birds with USGS bands and color bands to help with re-sighting in the future. We visited two more nests while the rain held but only came up with one more bird. He was not big enough to be equipped with a GPS transmitter but received a color band instead.

Female Broad-winged Hawk during data recording

Color bands on the female carrying a GPS transmitter

We will follow the movements of the female bird now named Ottauquechee to see where she goes during migration. Next spring we will determine if she returns to the same territory and if she is joined by her mate. This important project allows Hawk Mountain to learn more about Broad-winged Hawk migration and their nesting success. They are following broad wings from across their range and are gaining valuable insight into their movements. We hope to deploy more transmitters on Vermont birds in the future to help expand Hawk Mountain’s data. Since the VINS logo is a Broad-winged Hawk silhouette, we couldn’t think of a better project to help contribute to!

Vermont transmitters were funded by a generous grant from the Butler Foundation. All birds handled with proper state and federal permits and consideration taken to reduce the spread of Highly Pathogenic Avian Influenza.

VINS logo with Broad-winged Hawk silhouette

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